Two batteries, one of emf 18 volts and internal resistance 2Ω and the other of emf 12 volt and internal resistance 1Ω, are connected as shown. The voltmeter V will record a reading of.

                    

1.  18 volt

2.  30 volt

3.  14 volt

4.  15 volt

Voltage drop across the terminals of a cell of EMF 2V is 1V when 2 A current is drawn from it. Internal resistance of the cell is?

1.  $2\mathrm{\Omega }$

2.  $1\mathrm{\Omega }$

3.  $0.5\mathrm{\Omega }$

4.  $0.25\mathrm{\Omega }$

When current flows in steady state in the wire whose area of cross-section decreases as shown. Which of the following is incorrect?

1.  Drift speed increases in the direction of current.

2.  Electric field decreases in the direction of current.

3.  Electric Potential decreases in the direction of current.

4.  Current density increases in the direction of current.

‘N’ batteries each of emf E and internal resistance ‘r’ are first connected in series and then in parallel to an external resistance ‘R’. If current through ‘R’ is same in both cases then                      

1.  $\mathrm{R}={\mathrm{r}}^2/\mathrm{N}$

2.  $\mathrm{R}=\mathrm{Nr}/2$

3.  $\mathrm{R}=\mathrm{Nr}$

4.  $\mathrm{R}=\mathrm{r}$

During charging a capacitor, the variation of potential V of the capacitor with time t is shown as :

1. 

2. 

3. 

4. 

A set of '\(n\)' equal resistors, of value '\(R\)' each, are connected in series to a battery of emf '\(E\)' and internal resistance '\(R\)'. The current drawn is \(I.\) Now, if '\(n\)' resistors are connected in parallel to the same battery, then the current drawn becomes \(10I.\) The value of '\(n\)' is:

A carbon resistor (47 ± 4.7) kΩ is to be marked with rings of different colours for its identification. The colour code sequence will be:

1. Violet - Yellow - Orange - Silver

2. Yellow - Violet - Orange - Silver

3. Yellow - Green - Violet - Gold

4. Green - Orange - Violet - Gold

In the circuit in the figure, if the potential at point A is taken to be zero, the potential at point B is :

1. -1V                                          2. +2V

3. -2V                                          4. +1V

A potentiometer is an accurate and versatile device to make electrical measurements of E.M.F. because the method involves:

The potential difference \(V_{A}-V_{B}\) between the points \({A}\) and \({B}\) in the given figure is: